So, let's sort through this for Joe, because this is a question I get fairly often. First of all let's consider the primary conductor shown in the diagram above. It lists 4 AWG wire as the requirement. Its important to remember here that on a boat with an aluminum spar, the mast will serve as the primary down conductor. On boats with carbon fiber spars, the ABYC does not consider the spar a suitable conductor. Obviously, a wooden mast is not good either, an actual cable needs to be routed up the spar. I'm not sure whether Joe's Orion uses a wood or aluminum spar. I'm going to assume it is aluminum. Also important to know here is whether the mast is deck or keel stepped. If it is keel stepped, all that's needed is to run a 4 AWG cable from the mast base to one of the keel bolts.